Intestinal microbiota and secretory immunoglobulin A in feces of exclusively breast-fed infants with blood-streaked stools.

MedLine Citation:

PMID:
22725615
Owner:
NLM
Status:
Publisher

Abstract/OtherAbstract:

Episodes of streaked rectal bleeding are not uncommon in exclusively breast-fed infants less than 6 months of age. Although this rectal bleeding is thought to be associated with food protein-induced proctocolitis, the pathomechanism still remains unclear. The aim of this study was to investigate the intestinal microbiota and secretory immunoglobulin A in feces of breast-fed infants with streaked rectal bleeding. Fecal specimens from 15 full-term infants with streaked rectal bleeding, who had been delivered vaginally and breast-fed, were studied in comparison with similar specimens from 15 breast-fed healthy infants. We subjected the fecal microbiota to phylogenetic analysis and culture for some bacterial species, and examined the presence of fecal secretory immunoglobulin A by enzyme-linked immunosorbent assay. Phylogenetic cluster analysis revealed four major clusters of fecal bacteria, cluster A being found only in healthy infants. The Bacteroides fragilis group was observed more frequently in controls than in patients (p <0.05). The most dominant species belonging to the Enterobacteriaceae group in the controls was Escherichia coli, whereas in the patients Klebsiella was predominant (p <0.05). The levels of secretory immunoglobulin A were shown high in one third of the healthy controls. In conclusion, the pathomechanism of rectal bleeding in exclusively breast-fed infants may be related to the difference in formation of the intestinal flora.